On May 13, 1917, the Virgin Mary appeared to three shepherd children in the valley of Cova da Iria in the parish of Fatima in Portugal. She asked them to pray for peace in the world. The apparition was repeated for the next five months.
(The area was a little known poor hamlet. The people were simple, hard working peasants and were very isolated. That all changed after May 13th, 1917).
The children were promised a miracle so others would believe in the apparitions. October 13th, 1917 was the occasion of the "Miracle of the Sun" in which the sun spun toward the earth and the 70,000 people (many walked from days away to be present) were terrified.
It had rained for hours and they were soaked and noticed only after the sun retreated back up into the sky, that they and the ground were totally dry. The sun's path was studied and even unbelievers accepted the sign as a miracle.
Personal miracles occurred that day.
A little chapel was built on the spot where the Lady appeared. So many came to pray that in 1928, construction on a Basilica was begun. The edifice was completed in 1953.
All three of the seers are buried in the Basilica.
On the 13th day of the month from May 'til October hundreds of thousands of pilgrims gather at Fatima and fill the square which is twice the size of the square at the Vatican.
When I wander around the square, go into, the Basilica, or visit the chapel I think about the history of Fatima and its awesome message.